A number of commercially developed machines for digging in earth, particularly digging trenches in earth, have long been known in the construction industry. One of the most popular, efficient and cost-effective machines is a device known as a back-hoe, consisting generally of an excavating bucket attached by two or more linked arms to a vehicle such as a tractor, which provides the power to operate the device through two or more hydraulic pistons and connecting rods. Often the principal reason for trench digging is to place buried pipe, conduit or cable. To avoid subsidence or settling of the earth in the trench after refilling with earth, industry practice and often local governmental regulation, require that the floor of the trench and the earth used to refill the trench after placing the pipe or cable must be compacted. Effective compacting of the earth in the trench is usually accomplished by electrical, mechanical or pneumatic tamping machinery. Of necessity then, trench digging and filling requires more machinery and man power than just the back-hoe to dig and fill.
Over the years, in recognition of this problem, a number of inventions have been proposed to combine the earth-compacting function with the back-hoe earth-digging function to the end that only one piece of machinery be required. No prior device or invention has been able to achieve this end without substantial additional machinery, or substantial modification of the earth-digging machine, itself For example, in U.S. Pat. No. 3,891,342, the invention disclosed there required the complete removal of the excavating bucket to attach the earth-compacting invention. That arrangement is time-consuming and does not permit the earth-filling use of the bucket contemporaneously with the earth-compacting roller. U.S Pat. No. 3,595,411, discloses a similar invention wherein a compacting roller is mounted directly to the back of the excavating bucket, but the invention requires modification of the bucket, the attachment of devices to the bucket for the attachment of the invention and also contemplates a degree of accuracy in alignment of roller to bucket merely to attach the invention. In many instances in clay, mud, or wet soil, this too, is impractical. Finally, U.S. Pat. No. 4,100,688, conceived a means of attaching a roller for earth-tamping directly to a back-hoe excavating bucket by insertion of a highly modified link in the back-hoe connecting arms transmitting the digging force from the hydraulic pistons and connecting rods to the excavating bucket. This invention requires judicious selection of the material comprising the substituted link to avoid use of material which would be less strong than the factory-made link for the back-hoe machinery and a fairly high degree of machining accuracy and measurement to produce. The invention also possessed the draw-back of inserting a link into the manufacturer's design which if improperly made or installed could interfere with or weaken the back-hoe's earth-digging function. Lastly, that invention permitted the use of a roller which could never attain the width of the excavating bucket to reach to the very edges of the excavated trench, permitting a strip along both sides of the floor of the excavated trench to escape compaction.
The present invention avoids these problems by presenting a roller-compactor to be attached to the back of a back-hoe excavating bucket by the simple means of introducing a hole through the existing supporting ribs on the back-side of the excavating bucket and an attaching pin through that hole. The present invention allows the compacting roller to be speedily and easily attached to the back-hoe excavating bucket by hand lifting the attaching plate, aligning a hole or slot in the forementioned attaching plate over an existing link-pin at the excavating bucket's back-side and inserting one connecting pin. The roller permits the excavating bucket to continue its digging function while the roller is attached without hinderance or obstruction, while contemporaneously allowing the back-hoe operator to compact or tamp earth if he so wishes without removal, adjustment or modification of the invention. The present invention also permits the width of the roller to be extended to the same width as the excavating bucket, permitting the operator to compact the earth on the floor of the excavated trench right up the edges of the trench. If required or desired, the width of the roller can also be extended beyond the width of the excavating bucket for special applications.